Motor fuel



Patented June' 30, 1936 UNTED STATES MOTOR FUEL Hyym E. Buc, Roselle, N.J assignor to Standard Oil. Development Company,

Delaware a corporation of No Drawing. Application December 21, 1932,

Serial N0. 648,211

11 Claims.

This invention relates to motor fuels and methods of preparing same foruse in internal combustion engines and the like, and relates moreparticularly to motor fuels blended with agents which tend to reduce theknocking of the engine.-

Ethers have been added to motor fuels ,in the past and are generallyknown as knock inducers; but I have discovered that branched ethers,contrary to expectation, are particularly useful in reducing theknocking tendency of a hydrocarbon motor fuel such as the gasolineobtained from petroleum by known commercial methods. By the termbranched ethers is meant an ether of the general formula RrQ- R whereeither one or both R and R are branched hydrocarbon radicals, eitheralike or unlike. If only one is branched, the other may be any otherhydrocarbon radical, such as alkyl, aryl, etc. branched ethers which maybe prepared in general from secondary and tertiary alcohols by any ofthe well known methods are, according to the invention, blended with amotor fuel in any desired proportion, such as 5%, 30%, 50% or more.

. As one particular example, 30% of isopropyl ether is added to acommercial gasoline motor fuel. Tests indicate that the octane number(the higher, the-octane number the less tendency to knock) at 375 F. wasincreased from 68.2 to 77.5, 30 resulting in an increase of 9.3.. 'Thisanti-knock agent has an additional advantage in that it has a high leadsusceptibility, meaning that additions of lead tetraethyl willaccomplish a stillfurther increase in octane number. For example, 1 c.c. of lead tetraethyl added to the commercial gasoline used in the abovetests increased the octane number from 68.2 to 77.5 but adding 1 c. c.of lead tetraethyl to the blend of gasoline containing isopropylether'resulted in an octane number of 87.4, giving a leadsusceptibilityof about 10. Some relatively good anti-knock agents havepoor lead susceptibility.

The increase in octane number is roughly proportional to the amount ofanti-knock agent used,

15%, a correspondingly less anti-knock effect will be produced.

Instead of using isopropyl ether, 9. number" of other branched othersmay be used; for example, a tertiary butyl ether or mixed others such asa methyl tertiary butyl ether or methyl tertiary amyl ether, etc.

In addition to the advantages mentioned above, the branched etherscontemplated by theinvention also possess the valuable characteristicthat they may be blended in practically any proportion with hydrocarbonmotor fuels and one need Such so if less than 30% isopropyl ether isused, say

not be concerned with the subject of water tolerance as they-areinsoluble in water, the same as the hydrocarbon motor fuel. Alcohols arethe best previously known blending agents, but they have thedisadvantage of being dropped out 5 by slight additions of water.

Having thus described the invention, I do not desire to be limited byanyof the examples which have been given for the sake of illustrationonly but I desire to claim all novelty inherent in the 10 invention asfar as the prior art permits.

I claim:

, l. A motor fuel comprising a mixture of hydrocarbons boiling withinthe gasoline range having its octane number improved by an addition 15of a substantial amount of a normally liquid ether miscible withgasoline, and'boiling within the gasoline boiling range, and having thestructure R-O-R' in which at least one of R and R is a branchedaliphatic hydrocarbon radical and 20 both R and R are hydrocarbongroups.

2. A motor fuel according to the preceding claim in which at least oneof R and R is an aliphatic hydrocarbon radical containing a tertiarycarbon atom which is linked'to the ether oxygen.

3. A motor fuel according to claim 1 in which the ether constitutes atleast, 5% ofthe composition. r

4. A motor fuel according to claim 1 in which the ether constitutes from5 to of the com- 30 position.

5. A motor fuel according to claim 1 in which the octane number of thehydrocarbon mixture is further improved by the addition of an anti knockcomposition comprising a lead alkyl com- 5 pound.

6.1K motor fuel according to claim '1 in which the ether is isopropylether. '7. A motor fuel according to claim 1 in which the ether isisopropyl etheifland constitutes from 5 to 50% of .the fuel. v

8. A motor fuel comprising gasoline having its octane number improved byan addition of at least .5% of isopropyl ether.

value increased by admixture thereto of di-isopropyl ether in quantityranging from about 10-30%.

10. A. motor fuel comprising a mixture of hydrocarbons boiling withinthe gasoline range having its octane number improved by anaddition offrom 5 to 50% of methyl tertiary butyl ether. 0

11. A motor fuel comprising a mixture of hydrocarbons boiling within thegasoline range having its octane number improved by an addition of from5 to 50% of methyl tertiary amyl ether.

. I-IYYM E. BUG.

9. A gasoline motor fuel having its anti-knock I

